Skip to main content

Full text of "Text Book Of Mechanical Engineering"

See other formats

Spur Wheel Moulding.


The first operation is done by means of the traversing screw G
which slides the whole of F and E by the nut H, the latter being
fixed to the centre piece. The lifting and lowering is done by
the hand wheel jr, which by worm and worm wheel turns shaft K
and chain wheel L, and the sliding arm E is raised or depressed
by the chain which is fastened to each end and tightly wound
round wheel L. The third operation, the rotation of the arm F, is
effected by turning the shaft N from the handle M, and, the motion
passing through the change wheels is transferred to the worm
wheel o, which is fixed rigidly on the central portion of the

machine. Varying change wheels can be inserted in much the
same way as in a screw-cutting lathe, and the revolutions or
fractional parts made by the handle can be seen by means of the
graduated disc P, so that any part of a circumference, such as the
pitch of the teeth, can be accurately traversed by the mechanism
last explained. The teeth are then formed in the sand after the

;'     '                                                                           D